Worldwide SARS-CoV-2 Omicron variant infection: Emerging sub-variants and future vaccination perspectives.

The coronavirus disease 2019 (COVID-19) pandemic has sparked widespread concern globally, particularly with the Omicron variant and its sub-lineages emerging as the predominant cause of infection for nearly two years. Taiwan's successful containment of COVID-19, underscored by broad vaccine coverage, the utilization of anti-viral therapeutics, and timely response strategies, has resulted in reduced excess mortality. Moreover, there is a crucial need for a phased exit strategy, balancing efforts to curtail disease transmission with the mitigation of socioeconomic impacts from rigorous measures. In this review, we examined the evolution and the epidemiological landscape of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sub-variants in Taiwan as well as other countries of the world. We also critically evaluated the effectiveness of COVID-19 vaccines against various SARS-CoV-2 variants. Additionally, we addressed the advantages of heterologous immunization strategies, fluctuations in neutralizing antibody titers, and complexities in establishing protective correlates among swiftly mutating viral variants.

Immunologic difference between hypersensitivity to mosquito bite and hemophagocytic lymphohistiocytosis associated with Epstein-Barr virus infection.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening, virus-triggered immune disease. Hypersensitivity to mosquito bite (HMB), a presentation of Chronic Active Epstein-Barr Virus infection (CAEBV), may progress to HLH. This study aimed to investigate the immunologic difference between the HMB episodes and the HLH episodes associated with EBV infection. Immunologic changes of immunoglobulins, lymphocyte subsets, cytotoxicity, intracellular perforin and granzyme expressions, EBV virus load and known candidate genes for hereditary HLH were evaluated and compared. In 12 HLH episodes (12 patients) and 14 HMB episodes (4 patients), there were both decreased percentages of CD4+ and CD8+ and increased memory CD4+ and activated (CD2+HLADR+) lymphocytes. In contrast to HMB episodes that had higher IgE levels and EBV virus load predominantly in NK cells, those HLH episodes with virus load predominantly in CD3+ lymphocyte had decreased perforin expression and cytotoxicity that were recovered in the convalescence period. However, there was neither significant difference of total virus load in these episodes nor candidate genetic mutations responsible for hereditary HLH. In conclusion, decreased perforin expression in the HLH episodes with predominant-CD3+ EBV virus load is distinct from those HMB episodes with predominant-NK EBV virus load. Whether the presence of non-elevated memory CD4+ cells or activated lymphocytes (CD2+HLADR+) increases the mortality rate in the HLH episodes remains to be further warranted through larger-scale studies.

A simplified approach to assessing penile endothelial function in young individuals at risk of erectile dysfunction.

Erectile dysfunction (ED) reflects a risk for systemic cardiovascular diseases by virtue of a common etiology of vascular endothelial dysfunction, which is increasingly reported to affect young adults. On the basis of physiological phenomenon of reactive hyperemia (RH), systemic and penile endothelial functions in healthy young adults were compared with the use of digital data on arterial waveforms before and after RH induction. Between July 2009 and March 2011, 32 young adult volunteers with normal erectile functions were recruited. Questionnaires on medical histories and sexual functions and blood samples for testosterone and biochemical analyses were obtained. Dilatation index (DI) and penile arterial waveform amplitude (PAWA) ratios for assessing systemic and penile endothelial function were acquired with an air pressure sensing system on the arm and a penile arterial waveform analyzing system on the penis, respectively. A total cholesterol/high-density lipoprotein (TC/HDL) ratio greater than 4.1 was used to define high risk for ED. Remarkable positive correlation was noted between DI and PAWA ratio (r = .640, P < .001). DI showed significant positive associations with serum testosterone (P = .012) and serum HDL level, whereas it showed negative correlations with total triglyceride and glycosylated hemoglobulin levels, body weight, waist circumference, body mass index, and diastolic blood pressure. Similarly, the PAWA ratio showed significant positive correlations with serum testosterone (P < .001) and HDL levels, but negative associations with body weight, waist circumference, and body mass index. Both DI and PAWA ratio successfully identified participants at high risk for ED (eg, TC/HDL ratio > 4.1; P < .05). Our results demonstrated that penile endothelial function can be assessed by evaluating systemic endothelial function in young healthy adults for early identification of risk for ED.

Penile arterial waveform analyzing system for early identification of young adults with high risk of erectile dysfunction.

INTRODUCTION: High prevalence of erectile dysfunction in young adults has raised much concern regarding early identification of risk factors for timely intervention. AIM: This study aimed at identifying young males at risk through a novel penile arterial waveform analyzing system. METHODS: Between July 2009 and December 2010, 30 young adult volunteers of age 18 to 29 without known history of vascular diseases or erectile dysfunction were recruited. MAIN OUTCOME MEASURES: Basic demographic and anthropometric characteristics (i.e., age, body weight, body height, body mass index, waist circumference) were recorded. Blood samples were obtained for determining levels of testosterone, glycosylated hemoglobin, triglyceride, fasting sugar, low- and high-density lipoproteins (HDL). Data obtained from visual sexual stimulation (VSS) RigiScan and the penile arterial waveform amplitude (PAWA) ratios were compared in terms of their correlations with anthropometric and serum biochemical parameters using Pearson's correlation analysis. RESULTS: PAWA ratios were found to correlate with Rigidity (tip and base) (r = 0.425, P = 0.019 and r = 0.664, P < 0.001, respectively). Significant associations of PAWA ratios were noted not only with serum testosterone level but also with risk factors for metabolic and cardiovascular diseases including total triglyceride, HDL, age, waist circumference, body mass index, and diastolic blood pressure. However, VSS RigiScan failed in identifying significant correlations with HDL, age, and diastolic blood pressure. CONCLUSIONS: Not only could the penile waveform analyzing system assess penile endothelial function in young adults, but the results also showed significant associations with their serum testosterone levels and metabolic parameters. The findings suggest that PAWA ratio may serve as an indicator for early identification and treatment of young adults at risk of erectile dysfunction.

Penile arterial waveform analyzer for assessing penile vascular function in young adults.

Not only does erectile dysfunction (ED) reflect penile vascular disorder in the majority of patients, but it also implicates their high systemic cardiovascular risk. Based on the principle of reactive hyperemia after a brief period of penile ischemia, in this study, we tested the validity of a new Penile Arterial Waveform Analyzer (PAWA) in assessing the relative increase in post-ischemic penile perfusion. Twenty young adult males (mean age 24.24 ± 2.45) without known history of cardiovascular diseases were recruited, whose anthropometric characteristics were recorded and their serum testosterone levels as well as biochemical profiles were determined. A penile cuff was applied to each subject, with cuff pressure being increased from 80 to 250 mmHg, each for 4 min, followed by reperfusion for 7 min. By dividing the area under waveform contour of hyperemic and baseline signals after Ensemble Empirical Mode Decomposition (EEMD), a Penile Perfusion Index (PPI) was calculated. Penile Brachial Index (PBI) was also obtained for comparison. The results not only showed a significant agreement between PPI and serum testosterone levels, but also a superiority of PPI to PBI in distinguishing the high- and low-risk groups for potential ED (PPI: p = 0.039 vs. PBI: p = 0.147). PPI was also demonstrated to show significant correlations with waist circumference (p < 0.001), body mass index (p = 0.005), body weight, total triglyceride, high-density lipoprotein, and systolic and diastolic pressures (all p < 0.05). In conclusion, we proposed a portable and easy-to-operate system in assessing the relative increase in penile perfusion after brief ischemia. The PPI thus obtained correlated significantly with serum testosterone levels as well as key anthropometric and serum biochemical parameters even in apparently healthy young adults, suggesting its potential as a sensitive tool in monitoring penile vascular function and risk for ED.

Clinical and laboratory manifestations of Kikuchi's disease in children and differences between patients with and without prolonged fever.

BACKGROUND: Kikuchi's disease (KD) is characterized by cervical lymphadenopathy with or without fever. It has been recognized worldwide but seldom reported in pediatric patients. METHODS: From January 1985 through December 2001, 64 patients younger than 18 years of age with pathologic proof of KD were enrolled in this study. The clinical manifestations, laboratory data and outcomes were reviewed. RESULTS: There were 35 male patients and 29 female patients with age ranging from 2 to 18 years and a median age of 16. All patients had cervical lymphadenopathy except 1 who had generalized lymphadenopathy. Lymph nodes of 32 patients (50%) were painful or tender or both. Lymphadenopathy was unilateral in 52 patients (82.5%). Lymphadenopathy associated with fever was observed in 21 patients (32.8%). Other signs such as skin rash, hepatomegaly or body weight loss were less common. Twenty-six patients (40.6%) had leukopenia and 2 patients had leukocytosis. Nearly one-fourth of the patients had mild liver dysfunction. Virologic or immunologic studies were normal in most patients. Patients with prolonged fever were more likely to have leukopenia (P < 0.05). All patients recovered, but 1 developed systemic lupus erythematosus 5 years later, and the other had vasculitis syndrome 2 years later. CONCLUSIONS: The clinical presentation of KD in pediatric patients is similar to that of adults. KD is a benign, self-limiting disease; prolonged fever occurred only in 32.8% of pediatric patients in our cohort. Leukopenia was the only feature significantly associated with prolonged fever.

The effect of shoe soling tread groove width on the coefficient of friction with different sole materials, floors, and contaminants.

Tread groove design is very common in footwear. However, coefficient of friction (COF) measurements between the footwear material and floor using a slipmeter were commonly performed using flat footwear pads. Such measurements might underestimate the actual slip resistance of the footwear pad. This research investigates the effects of the tread groove width on the measured COF using four footwear materials, three floors, and four liquid-contamination conditions using a Brungraber Mark II slipmeter. The analysis of variance results indicated that the footwear material, floor, contamination conditions, and groove width were all significant (p < 0.0001) factors affecting the measured COF. The hypothesis that wider tread grooves result in higher COF values was true with some exceptions especially on oil contaminated floors. A regression model, with an R2 of 0.91, was established to describe and predict the relationship between the COF and the tread groove width under footwear material/floor/contamination conditions.